There are batteries in your remote control, your laptop, your smartphone, your tablet, your car and soon, if Tesla's Elon Musk has his way, in your home. That's right, Tesla attempting to bring its extensive knowledge of batteries from its electric cars to your house. Its $5 billion Gigafactory battery factory being built in Reno, Nevada, will probably play a role in this plan.

The big question is why you would need a large battery in your home. After all, you get constant power from your electric company, right?

There are actually some good reasons to have a home battery. Many electric utility companies offer peak hour pricing, which means the electricity you use at certain times of the day is dramatically more expensive than other times like nights and weekends.

If you could charge up a battery during non-peak hours, and then use it to help power your home during peak hours, you'd be saving money. You might even be able to sell some of the electricity back during periods of high demand, or it can keep your home running during a blackout. That's not all though.